strain.

The music stopped suddenly. He found himself eagerly hoping that there
would be more. In a few moments it began again, and he was listening to
the familiar strains of _The Rosary_. He had always liked the
song--Grace, too, had been fond of it. He wondered if she could be
playing to him, trying to soothe his fast-shattering nerves with music.
It pleased him to think that it might be so, although he had no reason
to suppose that Grace knew of the torture to which Dr. Hartmann was
subjecting him.

After a time, the final strains of _The Rosary_ died away, to be
followed by a German march, played by some military band. This, too, he
was glad to hear, although he found himself thinking that he preferred
_The Rosary_. As if in answer to his thoughts, it began again--he found
himself repeating the words to himself mechanically, and thinking of
Grace.

The music continued for long over an hour. Duvall noted with surprise
that while there were many other selections, _The Rosary_ was played
almost every other time. So often, in fact, did its strains break the
stillness, that he became annoyed--in his nervous state this constant
repetition of the song worried him. After a time he shuddered when he
heard it, hoping that each time would be the last. No one but an
imbecile, he muttered to himself, could enjoy playing a piece over and
over in that aimless fashion. When at last the impromptu concert had
ceased, and the silence about him was once more unbroken, he found
himself puzzling in vain over the matter, as though it had become of
vast importance to him.

After the music ceased, he realized how much it had helped him to endure
the two or more hours which had elapsed since Hartmann left him. His
real tortures were only just beginning. The constant blaze of light on
his face, the ceaseless effort to keep his eyes closed, to turn his head
away, in spite of the bonds which prevented it, once more almost
frenzied him. He fell to wondering whether Hartmann had been in earnest,
when he told him of the qualities of the violet rays. Could they in any
way affect his mind? The mere thought stimulated his imagination to such
an extent that already he was convinced that his senses were
wandering--that his mind was becoming sluggish and dull.

As hour after hour passed, this thought became almost a certainty. His
head began again to ache terribly, his eyes seemed to swim in pools of
liquid fire. Bright flashes of light darted th